Marchers walk past a burned-out business in Ferguson, Missouri, on their way to Jefferson City. Photograph: Jeff Roberson/AP

Hundreds of protesters in Missouri have a begun a week-long long march organised by the National Association for the Advancement of Colored People (NAACP), in a move designed to inspire the spirit of the civil rights movement of 1950s and 60s, following a grand jury’s decision not to indict officer Darren Wilson for the shooting of Michael Brown.

“This march is predicated on civil rights history and the equal rights legacy of the Selma to Montgomery march, nearly 50 years ago,” said NAACP president and chief executive Cornell William Brooks, speaking from the head of the march in a phone interview with the Guardian.

“We are seeking both justice for Michael Brown’s family and systemic reform for an outraged community and an outraged country looking for a fundamental change in the way in which policing is conducted.”

As Brooks spoke, cheers erupted around him.

The Selma to Montgomery marches of 1965 were led by Martin Luther King Jr and followed the death of a young black civil rights activist, Jimmie Lee Jackson, who was shot by an Alabama state trooper.

“Here we are, nearly 50 years on in 2014, commencing a similar march as a consequence of a young man losing his life at the hands of a police officer,” Brooks said.

The march started near the site of Brown’s shooting at the Canfield Green Apartments in Ferguson on Saturday afternoon. Over seven days, it will make its way to state governor Jay Nixon’s mansion in Jefferson City.

Organisers said they expected a core of around 100 people to complete the full march, with thousands taking part along the route. They hoped the final leg would draw the biggest crowds.

Brooks told the Guardian veterans of the civil rights movement had joined the march along with diverse group of protestors from a variety of ethnicities and from across the US.

“The mood is serious, but also expectant,” Brooks said, “not because the size of the injustice is small, but because they believe the capacity of Americans to change is large.”

Brown, an unarmed 18-year-old, was shot dead by Wilson on 9 August, leading to protests and rioting which reignited on Monday after the announcement that a grand jury would not indict the police officer over the young man’s death.

Elsewhere on Saturday, demonstrators disrupted shopping in suburban St Louis for a second day. Protesters marched through a Trader Joe’s store in Brentwood, about 10 miles south of Ferguson, around noon. After leaving they briefly blocked Eager Road, near Interstate 170.

Sixteen people were arrested in Ferguson on Friday night, during protests on Black Friday, the first shopping day after Thanksgiving. Approximately 100 protesters marched and blocked traffic on South Florrissant Road towards the Ferguson police department, which has seen some of the heaviest unrest since the grand jury’s decision on Monday.

Police said 15 of those arrested were from out of state, including eight from New York, amidst reports published by the New York Times that some protesters were affiliated with the Revolutionary Communist Party. One protester from New York was arrested for allegedly assaulting a police officer.

St Louis County police did not respond to a further request for clarification from the Guardian.

Protesters observed a heavy police and national guard presence in the area, with one, 26-year-old Ebonie Tyse, telling the Associated Press: “I served my country. I spent four years in the army, and I feel like that’s not what I served my country for.”

On Friday evening, governor Nixon announced he would call a special session of the Missouri general assembly, to provide further funding for the presence of the national guard and state highway patrol in Ferguson, indicating the governor plans to maintain a large police and military presence in the area.

“Time is of the essence,” Nixon said in a statement. “It is vital that we act quickly so that we can fulfill our obligation to the men and women who are so bravely and capably serving their fellow citizens.”

The arrests followed a day of peaceful sit-ins and demonstrations in the St Louis, Missouri area. A group of around 300 people temporarily shut down the Galleria mall in St Louis. Shopping centre workers as well as some shoppers joined the protests, which also drew criticism from many at the mall who were attempting to capitalise on the holiday sales.

Earlier in the day and on Thursday evening small groups staged flash protests at Walmart stores throughout the St Louis area.

There were demonstrations in cities around the US, including arrests made in Seattle, New York, Chicago and Oakland.